If you have access to Lookup Editor in Back-office, you will be able to add or change a statement message.
STEPS:
1. In Advantage Back-office, click the left sidebar menu.
2. Open the System menu.
3. Click on Lookup Editor
4. Click on the Filter button in the navigation bar:
5. Type "SMS" into the search field: 
6. Press "Enter" on your keyboard.
7. Select SMS Messages.
8. Click on the insert button in the navigation bar:
This will add another blank field to the list of SMS Messages:
9. Type an english message in the "English" field and/ or type an afrikaans message in the "Afrikaans" field
10. Select the Enabled option from the Active drop-down field.
11. Press "Tab" on your keyboard.
12. Click on the Save button in the navigation bar:
NOTE: For the change to take effect, close the Point of Sale application on ALL the computers, and log back in.